Fuel lines changed on 8.1s now one won't start

DaltonGang

Member
Aug 11, 2020
104
Boat Info
1995 SeaRay 370 Sundancer
Engines
8.1 Horizons
1995 sundancer 370 with 8.1 engines
Had a mechanic replace all fuel lines. He wanted to start the engines but has not contacted me in 2 weeks despite my many texts and calls. So I went to the boat and started them. Both started fine and idled then starboard died. (yes fuel is on) I checked for any fuel leaks also. I also switched tanks just to see if it helped.

I cranked it many times and nothing. it's not getting fuel. I think it burned off the fuel sitting in there which is why it did start at first and idled for a minute. All lines are tight, its not sucking air.
I disconnected a line that goes into the fuel cooler and no fuel came out at all. Not even a drip. I would think it would pour out. I even turned the fuel on at the manifold and I would think gravity would make some fuel come out.

So I'm told 2 things by my facebook group.
1) vapor lock and it needs primed with a bulb primer and temp gas can.
2) the shut off fuel solenoid is stuck closed. But I can't find it! Maybe its mounted to the actual tank and I overlooked it, i don't know. But the engines ran fine before the fuel lines were changed it would be odd this goes out right at this exact moment unless a wire was knocked off.

So I'm looking for any suggestions that may help me. I'm pretty pissed at the mechanic for doing 99% of the job and then disappearing and now I'm stuck missing out on great weather.
 
Do you have a fuel shutoff solenoid for the engines? Unless you added it, I would expect you to just have anti-siphon valves in '95... which, of course, would be what is preventing fuel from coming out due to "gravity"... in other words, it's doing it's job. But it could also be clogged. Speaking of clogs, if the vent line/fitting is clogged, that could cause the issue. But first, try pre-filling your fuel/water sep with gas. If need be, also use a bulb before the sep to draw gas to the sep.
 
Do you have a fuel shutoff solenoid for the engines? Unless you added it, I would expect you to just have anti-siphon valves in '95... which, of course, would be what is preventing fuel from coming out due to "gravity"... in other words, it's doing it's job. But it could also be clogged. Speaking of clogs, if the vent line/fitting is clogged, that could cause the issue. But first, try pre-filling your fuel/water sep with gas. If need be, also use a bulb before the sep to draw gas to the sep.

I didn't see the fuel shut off solenoids but I didn't look that hard for them. I would expect to see them pretty easily and I did find the floscan thing which measures fuel for the burn rate but that wouldn't be it.

Keep in mind, engines ran fine before the mechanic replaced the fuel lines so I don't think it would suddenly clog but I will look for it and check. So the fuel/water sep is the item that looks like an oil filter correct? So I would unscrew it and just fill it?

I was also going to take off the line going to the fuel cooler and use a bulb primer and temp gas can and see about filling that up to get it running. After it runs I would connect line and maybe it will start flowing.... ? this is what someone else suggested.
 
So thinking about it, I will unscrew the sep filter and if there is no gas in it then that really narrows down the issue. I see a lot of people fill them when putting them back in. So if its empty then I may just need to fill it and try to prime the line and it may fire right up. The thing is, they only redid the lines. I don't think they changed the sep filters so there should be gas in them already. They did have them all taped up because they painted the bracket black so maybe they are new filters, not sure. It seems like they would change them if they are thorough. I'll find out.
 
I don't think they changed the sep filters so there should be gas in them already.
You stated the engine ran for a short time and then died - which would empty the filter.
 
You stated the engine ran for a short time and then died - which would empty the filter.

True. I assumed it burned the fuel near the fuel cooler to throttle body. But you could be right. I thought that because it started right up. Ok well now I know how to narrow it down and possibly prime it at the needed section. Thanks
 
If fitted (that will depend on whether your original engines were EFI or not), the fuel shut off solenoid is located near the outlet of the fuel tank, on the bulkhead. The starboard motor shut off is on the face of the bulkhead and should be easy to find. follow the hose out of the tank. One goes to the generator and the other goes to the shutoff. The port one is on the side of the bulkhead, and a little harder to see. It is likely mounted upside down. They both have a knurled knob on the front which is a bypass, in case you have lost power to the solenoid. They are a continuous duty item, so the fuel path is only open when it is energized. Do you hear the fuel pump running when you put the start switch in the run position? Should run for a few seconds and then quit. You might try doing that 10 times or so to prime up the fuel lines. Also check how stuff is hooked up vs the motor that runs. Depending on how disassembled he got, it may just be that he accidently hooked the fuel/water sep up backwards, i.e. the tank is hooked to the outlet, and the fuel pump is hooked to the inlet.
 
Ok, got it all running. The fuel filters were changed with the line (which I'd expect) but no fuel was put in them. So withh one engine starting and running right away I didn't think it would be a problem with the other. But adding fuel to the filter and line did the trick. Thanks everyone, another issue resolved!
 
Sometimes you can change a filter, not fill it and the engine starts and keeps running just fine... other times, not. Still other times I can just turn the key on and off a bunch of times to try and fill the filter with the pump - but even that is hit or miss. Never really figured out why sometimes and not others.
 
I usually half fill the new fuel filter with seafoam during filter change out. Seafoam has a procedure for top end cleaning.
 

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